<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .one>div {
            font-size: 30px;
        }

        .san:hover {
            background-color: pink;
        }
    </style>
</head>

<body>
    <div class="one">
        一个
        <div class="tow">
            2两个
            <div class="san">
                <div>
                    nihao
                </div>
                三个
            </div>
        </div>
    </div>
    <script>
        let monve = ['你在干嘛', '我好想你', '吃饭了吗?']
        console.log(monve.join(','));
    </script>
</body>

</html>